I have multiple health issues that contribute to pain and mobility issues, including osteoarthritis, fibromialgia and an autoimmune disease attacking my lungs, sinuses, joints, and skin. It can make movement and exercising regularly difficult and painful. As painful as it is to exercise, not exercising in the long run results in more pain and fatigue.
My former rheumatologist when I was living in Illinois actually gave me extra pain meds to use before exercising to help "get me started," by making exercise less painful. Ironically with arthritis and other chronic pain conditions, taking meds to prevent pain generally allow a person to take less meds than using the same meds to treat the pain once it has gotten severe. I'd also suggest asking about fish oil - I take 2000mg in the am and 2000mg at night. I started taking it when I learned that I couldn't take any other antiinlammatory drugs. It's important to talk to your doctor first, because the fish oil can interact with some meds.
I would HIGHLY recommend checking with your local Arthritis Foundation, Department on Aging and Disability Resources, United Way, doctor, Health Department, YMCA, or google to see if you can find a warm water exercise program (the warmer, the better to start). I started my exercise in such a program, and it was awesome. Not only did it allow me to exercise painlessly, just being in the water relieved much of my pain. It's a shame that every community doesn't have access to such programs, but they are much more common than most people realize - they tend to be hidden treasures - hidden in plain sight, but invisible because they're rarely advertised or promoted.